*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19874
19880
19890
19901
19910
19921
199323
19941
19951
19966
199710
19980
19990
20000
20010
20020
20030
20045
20051
20061
20070
20080
20090
20103
20111
20120
20130
20140
20150
20160
20170
Total59